Effects of sublethal concentrations of copper and freshwater on behaviour in an estuarine gastropod Polinices sordidus

This study investigated the effects of contamination by copper and freshwater on the behaviour of the estuarine gastropod Polinices sordidus. The burying response was inhibited by both pollutants. In the case of copper, it was suggested that this response after 30 min could reflect toxicity after 96 h, i.e. the 96 h LC₅₀ and the 30 min ED₅₀ were very similar. P. sordidus responded to freshwater at concentrations well below the 96 h LC₅₀, suggesting that this species can detect sublethal concentrations of freshwater. Thus, for salinity, the 30 min ED₅₀ is not a reliable indicator of the 96 h LC₅₀. A linear decline in crawling activity was found in the presence of increasing concentrations of both pollutants. These results for both aspects of behaviour are discussed in the light of results reported earlier for a marine species Polinices incei.     

Toxicity of sediment-incorporated drilling fluids

The 24, 96, or 168h LC₅₀s of four used drilling fluids or barite incorporated into sediment were determined in toxicity tests with lancelets (Branchiostoma caribaeum), a benthic chordate. Concurrent to LC₅₀ determinations, EC₅₀s were calculated from the number of lancelets that did not burrow into contaminated sediments. Observations of the burrowing behaviour allowed quantitation of effects after 24h exposures to each of the drilling fluids whereas lancelet mortality was sufficient to calculate 24h LC₅₀s for only one drilling fluid. Drilling fluids were less toxic to lancelets when incorporated into sediments than to mysids (Mysidopsis bahia) or benthic invertebrate communities in water-column exposures.     

The effect of heavy metals on the survival,reproduction, development,and life cycles for two species of polychaetous annelids

The effects of exposure of six metals on survival and reproduction in two species of polychaetous, Ctenodrilus serratus and Ophryotrocha diadema, possessing short life histories were measured. The suppression of reproduction was generally two orders of magnitude less than the 96 h LC₅₀.     

Persistent halogenated compounds in two typical marine aquaculture zones of South China

Samples of two seawater farmed fish (crimson snapper (Lutjanus erythopterus) and snubnose pompano (Trachinotus blochii)), water, air, sediment, fish feed, macroalgae and phytoplankton were collected from two estuarine bays (Daya Bay and Hailing Bay) in South China. The concentrations of persistent halogenated compounds (PHCs) including polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and polychlorinated biphenyls (PCBs) varied widely with the different sample matrices under investigation. The compositional patterns in fish, fish feed, macroalgae and phytoplankton, as well as the good correlations between the abundances of p,p′-DDT and BDE-209 and their metabolites (i.e., p,p′-DDD and p,p′-DDE for p,p′-DDT and BDE-47 for BDE-209) in fish indicated the occurrence of DDT and PBDE biotransformation in fish body. Finally, the marine aquaculture environment in South China is somewhat biologically impaired by DDT-contaminated water, sediment and fish feed, and there may be some cancer risk associated with fish consumption for humans, especially for urban residents.     

Acute toxicity of copper to a copepod

The acute toxicity of copper to the marine copepod Acartia clausi was determined by means of static bioassays. Natural copepod assemblages from two different locations, one from an area polluted with industrial effluents and domestic wastes and another from a relatively uncontaminated area, were compared. Results of metal toxicity tests expressed as 48 h LC₅₀ values indicate a significant difference in the tolerance of copper between the two populations, with the LC₅₀ of the pollution-adapted population higher than that of the population from the uncontaminated area.     

Toxicity of Interactions of Zinc —Nickel,Copper —Nickel and Zinc —Nickel —Copper to a Freshwater Teleost,Lebistes reticulatus (PETERS)1

The lethal toxicity of mixtures of Zn²⁺ —Ni²⁺, Cu²⁺ —Ni²⁺ and Zn²⁺ —Cu²⁺ —Ni²⁺ to common guppy at 21£C in hard water (total hardness = 260 mg/l as CaCO₃) was studied under static bioassays test conditions with renewal of the test solutions every 24 h. The heavy metals were tested separately and in mixtures. The 48 h median lethal concentrations (LC₅₀) for individual salts were 75 mg/l Zn²⁺, 37 mg/l for Ni²⁺ and 2.5 mg/l for Cu²⁺. Concentrations were expressed in “toxic units” by taking them as proportions of LC₅₀ values. Experiments showed that in the Zn²⁺-Ni²⁺ mixture, when Ni²⁺ was more in proportion, the toxicity was more than additive. The 48 h LC₅₀ value and 95% confidence limits in the Ni²⁺-Cu²⁺ mixture were 0.684 (0.484 … 0.807) toxic units and the mixture produced more than the additive toxicity (synergism.). The LC₅₀ value and its 95% confidence limits in a Zn²⁺?Cu²⁺?Ni²⁺ mixture also suggested that the mixture was again strictly additive. The results indicate that heavy metallic mixtures would pose a greater toxicological danger to fish than the respective individual metals.     

Toxicological effects of biocide Slimicide C-30 on some marine invertebrates

Sublethal and lethal effects of biocide Slimicide C-30 on the developmental stages of mussels Mytilus galloprovincialis and juvenile and adult mysid Leptomysis mediterranea were studied.Biocide at a concentration as low as 0.02 mg l^?1 caused an incipient effect in the embryonic development of mussels where a decreased number of normally developed larvae from eggs was evident. Slimicide C-30 effective concentration (EC 50/96) was 0.07 mg l^?1.In the mysids, the median lethal concentration (96 h LC₅₀) was 0.11 mg l^?1.Previous incubation of Slimicide C-30 at 38°C affected a small delay in mortality time (LT₅₀) but did not cause marked change in the acute toxicity to mysids.     

Effects of Scotian shelf natural gas condensate on the mummichog

The 96h LC₅₀ of the water soluble fraction (WSF) of natural gas condensate from the Sable Is., N.S. area to Fundulus heteroclitus was between 4 and 5 μg · ml⁻¹ naphthalene equivalents (initial concentration). Behavioural responses in the fish to sub-lethal concentrations of WSF were similar to those recorded for crude and fuel oils. Induction of the hepatic mixed function oxidase enzyme enthoxyresorufin O-de-ethylase (EROD) in sexually immature fish occurred at WSF concentrations below the LC₅₀, but during the prespawning period no induction occurred. EROD activity in unexposed fish showed seasonal variation consistent with differences in its inducibility.     

Short Term Effects of Aldrin and Swascofix CD-38 on the Feeding and Respiratory Behaviours of Clarias batrachus and Cirrhina mrigala

Fish were kept in non-toxic water or at 0.5, 0.25 and 0.125 of the LC_50,96h of the ten-side or insecticide for 24 h and fed with toxified and non-toxified feed. Toxified feed in normal water resulted in a maximum feed intake, while normal feed in toxified water resulted in a minimum one. In each case, the feed intake was lower compared with the control, and the feed intake was inversely proportional to the toxicant concentration. In a simple respirometer the oxygen consumption in mg · kg^?1 · h^?1 was tested for 1, 2, 4, 6, 8, 10, 12, 24, 36, 48, 60, 72, 84 and 96 h of exposure to 1.5, 1.0 and 0.5 of the LC_50,96h of both substances. It was a flow device which was closed only for measurement for one hour. 1.5 LC₅₀ Aldrin causes a continuous reduction of respiration until death. The same effect occurred with Cl. batrachus for 1.5 LC₅₀ of the tenside, whereas with C. mrigala death was caused by a pronounced increase of respiration. In all other cases, after a phase of sensitization for 4 … 8 h respiration increased considerably to more than 300% of the control, which was followed after 12 … 24 h by acclimatization to normal respiration values.     

Phthalate ester plasticizers,DDT, DDE and polychlorinated biphenyls in biota from the Gulf of Mexico

The levels of phthalate ester plasticizers, DDT, DDE and polychlorinated biphenyls (PCBs) were determined in the tissues of 18 species of marine organisms from the northwestern Gulf of Mexico. Low levels of the most widely used phthalate, di-(2-ethylhexyl) phthalate, were found in the majority of the samples; no other phthalates were detected. DDT, DDE and PCBs were found in all samples, but at somewhat lower levels than those found in our 1971 survey. A decrease in p,p′-DDT/p,p′-DDE ratios relative to 1971 was also noted.     

Acute toxicity of copper to sea catfish

Sea catfish (Arius felis) were exposed to aqueous solutions of reagent grade cupric chloride in artificial seawater ($\text{30.0±2.0‰}$, 21–23°C) in four static bioassays. The 24, 48, 72 and 96 h LC₅₀ were calculated and found to be 5.43, 4.17, 3.57 and 2.40 mg l.^?1 copper, respectively. Experimental concentrations of copper producing subtle behavioral changes in this species correspond to less than 0.3% of the 72 h LC₅₀. Based on this comparison with literature values, a new, maximum ‘safe’ concentration for copper in marine waters of 0.01 mg l.^?1 is proposed.     

Acute Toxicity of Phenol,Pentachlorophenol and Sodium Pentachlorophenate to a Freshwater Ostracod Cypris subglobosa (Sowerby)

The toxicity of phenol, pentachlorophenol and Na-pentachlorophenate to Cypris subglobosa is determined in the batch experiment for 96. h. In the sequence mentioned, the LC_50,96h of the three substances are 71.8, 6.56 and 4.41 mg/l, respectively. In the range of 6 … 95 h the mean survival time shows a negative regression to the toxicant concentration, which, however, is not significant statistically for Na-pentachlorophenate. In agreement with this, the LC₅₀ for 12, 24, 48, 72 and 96 h of exposure shows a significant decrease. Due to the comparatively high LC_50,96h for pentachlorophenol and Na-pentachlorophenate for C. subglobosa about in comparison with fish, the species is little suited to the toxicological investigation of wastewater.     

The acute toxicity of silver to some freshwater fishes

In the batch experiment with daily exchange of medium the acute toxicity of Ag from AgNO₃ to Channa punctatus, Lebistes reticulatus and Puntius sophore is determined over 12 to 96 h exposure. In general, the sensitivity of species increases in the order mentioned. The LC_{50, 96h} are 18.89 μg/l Ag for Channa punctatus, 7.55 μg/l Ag for Puntius sophore and 6.44 μg/l for Lebistes reticulatus. For 12 and 48 h exposure the values in the same order of species are: 62 and 30, 44 and 14 as well as 57 and 16 μg/l Ag.     

Biological accumulation of chlordane compounds in marine organisms from the northern North Pacific and Bering Sea

Sum of chlordane compounds (ΣCHL; cis-chlordane + trans-chlordane + cis-nonachlor + trans-nonachlor + oxychlordane) are concentrated gradually with trophic levels from zooplankton to Dall's porpoise (Phocoenoides dalli) through squid and fish. The order of bioconcentration factors (BCF: concentration in organism/concentration in seawater) in these organisms was ΣDDT (p,p′-DDE + p,p′-DDD + p,p′-DDT)>ΣCHL≦PCBs>ΣHCH (α-HCH + β-HCH + γ-HCH). Calculation for the concentration factor against food, namely biomagnification factor (BMF: concentration in organism/concentration in its food), was made for Dall's porpoise and thick-billed murre (Uria lomvia). The BMFs of these chemicals in thick-billed murre were lower than those of Dall's porpoise, suggesting the degradation and/or excretion of organochlorines through the uropygial gland with lipids. Moreover, the lowest BMF of ΣCHL in thick-billed murre among organochlorines may indicate that chlordane compounds (CHLs) are metabolized more rapidly by this seabird than Dall's porpoise.     

Chemical composition and acute toxicity in the water after in situ burning--a laboratory experiment

The chemical composition and toxicity of a water soluble fraction (WSF) of oil versus the underlying water after in situ burning (ISB), has been studied in a laboratory experiment. A system for allowing water sampling after ISB was developed. Seawater samples and oil were collected prior to and immediately after ISB, and chemical analysis was conducted. The chemical characterization of the water showed that the disappearance of water soluble oil components during ISB was insignificant. Acute toxicity tests with the marine copepod Calanus finmarchicus and Microtox® bioassay was performed to establish LC₅₀/EC₅₀ values of the water. The results were compared with regular WAF systems with unburned weathered oil, and indicated no increase in toxicity in the underlying water after ISB.     

Comparative Toxicity of Heavy Metals and Interaction of Metals on a Freshwater Pulmonate Snail Lymnaea acuminata (Lamarck)

In static bioassays the toxicity of heavy metal ions against Lymnaea acuminata over 24 … 96 h is tested. The values of the LC_50,96h for the metals tested are, in mg/l: Hg²⁺ ?0.023; Cu²⁺-0.034, Cd²⁺ ?0.872, Ni²⁺ ?2.78, Cr⁶⁺ ?5.97 and Zn²⁺ ?10.49. In the combined solutions of Cu²⁺, Ni²⁺ and Zn²⁺ at least an additive effect of toxicity occurs in the presence of two metals. The same holds for the presence of the three metals; in this case, the relative toxicity against the mixture of two metallic salt solutions appears to be slightly reduced. The acute manifestation of the toxic effect occurs within 48 h, subsequently the relative mortality decreases especially in the mixed solutions.     

A Study on the Effect of Temperature upon the Toxicity of Sodium Pentachlorophenate to the Freshwater Snail Viviparus bengalensis L.

The toxicity of Na-pentachlorophenate to Viviparus bengalensis is investigated by batch tests with daily exchange of medium in the temperature range between 19 °C (February), 27 °C (April), 32 °C (June) and 30 °C (August) at times of exposure between 12 and 96 h. In the range of higher concentrations, pronounced abnormalities in behaviour by secreting mucus and discharging eggs and embryos occur. The LC₅₀ are lowest for all times of exposure at 27 °C, whereas the times of survival with a given concentration are highest at 30 °C. From the LC_{50, 96h, 27°C} = 66 μg/l results a safe concentration of only 47 μg/l Na-pentachlorophenate for Viviparus bengalensis.     

Temperature and accumulation of DDT by sea mullet (Mugil cephalus L.)

Accumulation of tech-DDT by the sea mullet Mugil cephalus L. was investigated at 15, 20, 25 and 30°C. Tissue residues of p,p′-DDT in fish increased with temperature reflecting an increase in metabolic rate. Metabolic degradation of p,p′-DDT to p,p′-DDD was also indicated. Rate of uptake of p,p′-DDT (mg kg^?1 h^?1) was not positively correlated with temperature and decreased with time at 15, 25 and 30°C. These results suggest that the uptake of DDT from water can be regulated by M. cephalus.     

Influence of Temperature on the Toxicity of Phenol and its Chloro- and Nitro-derivatives to the Fish Notopterus notopterus (PALLAS)

There is determined the LC₅₀ for 24 … 96 h of phenol, 2,4-dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.     

Acute toxicity of platinum to coho salmon (Oncorhynchus kisutch)

The effects of short-term exposure to tetravalent platinum on survival, opercular movement and post-treatment growth of coho salmon fry (Oncorhynchus kisutch) was investigated. Employing a static water acute toxicity bioassay with platinum as PtCl₄2HCl·6 H₂O, at 8.5±0.2°C, and a water hardness of 55.9±3.5 mg l.^?1 (as CaCo₃), the 24, 48, and 96-h LC₅₀ values were 15.5, 5.2, and 2.5 mg Pt⁴⁺ l.^?1 respectively.Rates of opercular movement for fish exposed to platinum increased with increasing concentrations to a level of 1.0 mg l.^?1. No further significant increases were evident above this level. Hypoactivity of fish exposed to 0.3 mg l.^?1 and higher was evident during the acute toxicity bioassay and much of the post-treatment study. Post-treatment rate of growth for fish exposed to sublethal concentration of platinum for 96 h was less than that of the controls.All organs examined histopathologically were within normal ranges with the exception of the gills and olfactory organ. Lesions in fish exposed to concentration of 0.3 mg l.^?1 and higher were characterized by branchial epithelial hypertrophy and hyperplasia, and necrosis of olfactory epithelial cells.